From particles to films: production of Cs2AgBiBr6-based perovskite solar cells and enhancement of cell performance via ionic liquid utilization at the TiO2/perovskite interface.

Herein, Cs2AgBiBr6 particles produced by the traditional super-saturation precipitation method were used as precursors to create Cs2AgBiBr6 films by the gas-quenching process under ambient atmospheric conditions. These films were utilized as a light-absorbing layer in hole-transporting free perovskite solar cells (PSCs) with carbon electrodes. Furthermore, the incorporation of the 1-butyl-3-methylimidazole hexafluorophosphate (BMIMPF6) ionic liquid (IL) at the metal oxide electron transporting layer/perovskite interface resulted in enhanced crystallinity of the perovskite, forming large perovskite grains of up to 800 nm. However, it was discovered that establishing the optimal concentration for passivating surface defects takes precedence over encouraging the growth of larger perovskite grains. The utilization of the optimized BMIMPF6 concentration led to a remarkable increase in the power conversion efficiency (PCE) of the cell, with a boost of over 31% to reach 1.67%, when compared to the cell produced without the inclusion of the IL. Our findings underscore that the passivation of surface defects between the TiO2 and perovskite layers holds more importance for enhancing the PCE of Cs2AgBiBr6-based perovskite solar cells than focusing solely on the perovskite morphology.

UV/visible light active CuCrO2 nanoparticle-SnO2 nanofiber p-n heterostructured photocatalysts for photocatalytic applications.

CuCrO2 nanoparticle decorated SnO2 nanofiber composites have been prepared as novel p-n heterostructured semiconductor photocatalysts for the degradation of organic pollutants in wastewater. The composite structure was achieved via drop casting of various amounts of hydrothermally derived CuCrO2 nanoparticles on electrospun SnO2 nanofibers. The microstructural and morphological features of each semiconductor and the formation of p-n heterojunctions between them were characterized. In addition, the photo-response and electrochemical properties of the samples were determined. The photocatalytic activity of the heterostructured photocatalysts was investigated systematically as a function of the amount of CuCrO2 nanoparticles in the samples. Experimental results showed that the optimal decoration amount was 0.6 wt% CuCrO2 on SnO2. This composite photocatalyst displayed a 41% higher rate constant value compared to pure SnO2 nanofibers in the degradation of methylene blue dye molecules and reached 83% degradation under UV/visible light irradiation after 1 h. The increase in the photocatalytic activity was ascribed to the incorporation of Cr3+ and Cu+ cations into the SnO2 host lattice and the more effective electron-hole pair separation in the heterostructured sample. The presented data here are highly convincing in comparison to those of UV active p-n heterostructured photocatalysts reported previously in the literature. Therefore, this work opens the way to develop visible light active p-n heterostructured semiconductor photocatalysts using p-type delafossites with n-type oxides.